Background: Clinical trials report PFO closure to decrease the long-term risk of recurrent paradoxical stroke. We previously found that PFO is not just a back door to clotting, but may increase the risk of chronic neurovascular injury via venous arterial mixing resulting in elevated oxidative mediators. In this study, we prospectively explore the relationship of PFO shunting and chronic WMH, a surrogate for chronic neurovascular injury, compared to non-PFO-related cryptogenic stroke (CS).
Method: PFO and non-PFO CS patients were consecutively recruited in accordance with IRB (n=81 PFO; n=98 non-PFO CS). WMHs were scored by vascular neurologist blinded to patient outcome.
Result: Compared to CS without PFO, PFO pts had increased WMH burden as measured by Scheltens scale. WMH burden was independently associated with PFO after adjusting for age, gender, NIHSS and disease status (odds ratio: 1.19, p = 0.003). Moreover, in pts s/p PFO closure, WMH score was significantly higher in those with residual shunting as compared with complete closure (Figure 1, 1 vs 8.25, p = 0.038).
Conclusion: Our results suggest an important association between PFO-related blood shunting and chronic neurovascular injury as measured by cerebral WMH. Studies in a larger patient cohort are ongoing to investigate the mechanistic relationship between PFO shunting and WMH.